Energy Star Rating question.

[Henson31]

Does a single family home being deigned under the “Energy Star System” require that the HVAC system have a ducted outdoor source?

Per IMC 402.1 and ASHREA 62.1 2007 section 5.1 “Natural ventilation” (AKA windows) is acceptable for ventilation. I’m not an Energy Star Rater but from what I see as long as the house is built per code and is ventilated per ASHREA 62.1 the building can still be rated without mechanical ventilation.

Please respond if you have any insight on this. Tracing down Energy Star requirements is not easy. All help would be appreciated.

Thanks

[HVAC dawg]

I think your right!:anyone:

[mbarson]

If your house is reasonably tight you will want mechanical ventilation. If you are building for Energy Star your rater should be able to tell you this based on the inputs into the rating software. I'm not sure what code allows windows to be used for ventilation except in bathrooms (prior) but not whole house ventilation. This is calculated by taking the number of people or (number of bedroom + 1) X7.5 cfm plus conditioned floor area x .01 cfm or .35 air changes per hour whichever is greater or there is a simple table to follow. This is for continuous ventilation. The ventilation system does not need to be tied into the HVAC system, there are many options. I'm not sue if you meant the HVAC system needing combustion air ducted from outdoors but that's something else.
62.1 is for commercial buildings you need 62.2 for residential buildings.

[teddy bear]

Does a single family home being deigned under the “Energy Star System” require that the HVAC system have a ducted outdoor source?

Per IMC 402.1 and ASHREA 62.1 2007 section 5.1 “Natural ventilation” (AKA windows) is acceptable for ventilation. I’m not an Energy Star Rater but from what I see as long as the house is built per code and is ventilated per ASHREA 62.1 the building can still be rated without mechanical ventilation.

Please respond if you have any insight on this. Tracing down Energy Star requirements is not easy. All help would be appreciated.

Thanks
Current ASHRAE suggest a minimum of 7 cfm of fresh air per bedroom plus 7 cfm for the master plus 1 cfm per 100 sqft. of living space as minimum. Also most expert sugest maintaining <50%RH to avoid dustmites/mold.
In green grass climates whole house ventilating dehumidifier for green grass climate is a device that is capable of fresh air ventilation and dehumidification during cool wet weather in green grass climates. Ultra-Air/Honeywell/Rheen etc are unit that are capable of providing fresh air ventilation and maintaining <50%RH throughout the home. During outside damp weather, the moisture from occupants and fresh air make a home damp while there is low/no cooling load to operate the a/c to remove moisture.
Regards TB

[jimj]

Does a single family home being deigned under the “Energy Star System” require that the HVAC system have a ducted outdoor source?

Per IMC 402.1 and ASHREA 62.1 2007 section 5.1 “Natural ventilation” (AKA windows) is acceptable for ventilation. I’m not an Energy Star Rater but from what I see as long as the house is built per code and is ventilated per ASHREA 62.1 the building can still be rated without mechanical ventilation.

Please respond if you have any insight on this. Tracing down Energy Star requirements is not easy. All help would be appreciated.

Thanks

If I am not mistaken it is based on your climate zone. In Hot and Humid climates I believe you are correct.